Linux 2.6.37 has been released. This release includes several SMP scalability improvements for Ext4 and XFS, complete removal of the Big Kernel Lock, support for per-cgroup IO throttling, a network device based in the Ceph clustered filesystem, several Btrfs improvements, more efficient static probes, perf support to probe modules and listing of accesible local and global variables, image hibernation using LZO compression, PPP over IPv4 support, several networking microoptimizations and many other small changes, improvements and new drivers. You can read the full changelog as well.

I thought they had removed this a while ago. What actually happened is that they gradually lessened the impact of The Big Kernel lock, allowing more and more of the kernel to be run in parallel. The only think it controls in modern 2.6 kernels are a hand full of drivers and obscure file systems. They fully removed the Big Kernel lock and replaced it with mutexes. So these parts that were not able to be run in parallel, are still not able to run in parallel, but one obscure driver shouldn't block a different obscure driver anymore. For what that's worth.

Still a pretty cool benchmark for the kernel. Oh, I remember the taunts of those who criticised the linux 2.0 kernel for its SMP. Nice to lay those to rest.

That combined with the recent scheduler changes in 2.6.38 and lots of changes to the kernel-threads, some tickless changes and ext4 scalability improvements and removal of barriers in the block subsystem should hopefully improve performance for a bit.